A variety of structures of window drains are known in the art. For example, in the case where a window drain is installed underneath a sash window frame, a window drain having a vertical portion which is fixable to a wall and further wherein the vertical portion has holes (openings) for accepting a screw to fix the window drain is known. The hole extends downwardly and an end of the hole is open so that an adjustment in a vertical direction can be carried out easily. Further, a window drain may have a round concave portion so that sealing material can be filled into the space between an external wall and the window drain. (JP 08-100578 A.)
Further, a window drain for preventing rain water drops can be installed beneath a sash window frame so that the window drain extends from an external wall so as to prevent stains caused by rain water and damage caused by frozen water. Such a window drain has a guide portion and a contact portion contacting an external wall. The guide portion has an upper portion inclining downwardly, a front portion extending vertically, a curved portion which smoothly connects the upper portion and the front portion, and a curve at the end of the front portion. (JP 2004-353198 A).
However, it is usually necessary to provide a space of approximately 10 mm, for example, so that a sealing material can be installed and fixed between a lower portion of the window frame and an upper portion of the external wall. In accordance with the method of JP 08-100578 A, there are drawbacks. For example, another sealing means must be employed and fixed at the proximity of an upper portion of a window drain so as to seal the space between a window drain and the external wall. Consequently, two (2) sealing portions are visible and the appearance at the proximity of the window drain is impaired. Further, when such a window drain is installed, it is usually necessary for a worker(s) to install and fix the window drain in a suitable position with screws, while holding the window drain by hand. Such a process is troublesome, and also it is difficult to install and fix a window drain in the correct position.